Watch-balance



(No Model.)

O. K. GILES.

WATCH BALANCE. N0. 887,973. Patented'Aug. 14, 1888.

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UNITED STATES PATENT if CHARLES K. GILES, OF. CHICAGO, ILLlXOlS.

WATCH-BALANC' SPECIFICATION forming part of Letters Patent No. 387,973,dated August 14, 1888,

Application filed December 2, 1887. Serial No. 256.532.

T0 aZZ whom it may concern:

Be it known that 1, CHARLES K. GILns, a citizen of the United States,residing at Ohicago, in the county of Cook and State of Illinois, haveinvented a certain new and useful Improvement in Watch Balances, whichis fully set forth in the following specification, reference being badto the accompanying drawings, in which- Figure 1 is a plan view of abalancewheel embodying my invention; Fig. 2, a sectional view of thesame, taken on the linel 1 of Fig. 1; and Fig. 3, a plan view showing amodified form of balancewheel.

Like letters refer tolike ures of the drawings.

My invention relates to balance-wheels for Watches, clocks,chronometers, and other like instruments for measuring time, and has forits object to provide a device of this description which shall possessthe advantages of superior simplicity, eheapness, and efficiency.

To these ends my invention consists in certain novel features, which Iwill now proceed to describe, and will then particularly point out inthe claims.

In Figs. 1 and 2 ofthe drawings Ihave shown a balance-wheel in which myinvention is practically embodied in one form. A represents the crossbarof the balance-wheel, to the ends of which are attached the arms orsections B and B of the rim. lhese arms, instead of being constructed oftwo metals of unequal expansion, are each constructed of a single pieceof metal, and are provided with the usual poising and adjusting screws,1). 0 represents an Sshaped cross-bar attached at its center to thecross-bar A, as shown at c, and having one of its ends attached to thearm or section B ofthe rim, while the other end is attached to the armor section B. This cross bar 0 may be considered as composed of twoequal halves, which, starting from the central point of attachment, 0,consist each ofa memher, 0, extending away from that arm of the rim towhich it is ultimately connected, and a member, G, connected to the endof the member G and extending in a reverse direction to the arm orsection B or B, as the case may be.

The member 0 is preferably constructed of parts in all the fig somemetal or material which expands and (N0 model.)

contracts to a considerable extent under varying temperatures, while themember 0 is constructed of a metal which is comparatively unaffected bychanges in temperature. The same result may of course be obtained byconstructing the member (1 of two different metals, one half ofwhieh isaffected to substantially the same extent as the member 0, while theother half is not affected by changes in temperature. It will thus beseen that upon an increase in the temperature the expansion of themember 0 will, owing to its connection with the arm B or B, counteractthe lateral expansion of the balance-wheel, the converse being true uponany decrease in the temperature, so that compensation for the changes intemperature will be obtained in an obvious manner. Moreover, the twohalves of the cross-bar 0 being symmetrical, the two halves of thebalance-wheel will be equally affected. It will be observed, moreover,that whereas in the ordinary construction of balancewheel, in which therim is composed of two metals which are affected by heat to an unequaldc grce, the said rim is moved inward or outward by alterations in itsshape produced by this inequality, and in thus moving curls inward oroutward at its ends in an irregular curve, which produces inequalitiesin the movement of the balance wheel, in the construction which I havedevised each half of the rim is moved bodily in an even manner, and isnot distorted in the man nor just set forth, whereby one of theprincipal sources of error is avoided.

In Fig. 3 of the drawings 1 have shown a modified form ol balance-wheel,in which the crossbar 0, instead of being arranged at right angles tothe cross-ha r A and connected to the arms B and 13 about midway betweentheir fixed and free ends, isarranged diagonally with relation to thesaid crossbar A, so that its ends are connected to the arms l5 and Bnear the free ends of said arms. By reason of this construction I amenabled to move the said rims inward or outward by means of their freeends, and thus cause them to assume more desirable shapes and.positions.

It is obvious that various modifications in the details of constructionmay be made without departing from the principle of my invention, and Itherefore do not wish. to be underthe main cross-bar A, and the arms BB, at-

tached thereto and each composed of asingle 15 piece, of the S-shapedcross-bar 0, attached centrally to the cross-bar A and consisting of twosyn'imetrical halves, each composed of a member, 0, and a member, 0 thelatter be ing of a material expansive to a degree equal 20 to orlessthan the material of the former, substantially as and for the purposesspecified. CHARLES K. GILES. Witnesses:

CARRIE FEIGEL, A. M. BEs'r.

